Refactor exchange table

activity_browser/app/bwutils/commontasks.py

@@ -109,6 +109,7 @@ def is_technosphere_db(db_name):
     "Location": "location",
     "Database": "database",
     "Uncertainty": "uncertainty type",
+    "Formula": "formula",
 }
 
 bw_keys_to_AB_names = {v: k for k, v in AB_names_to_bw_keys.items()}

activity_browser/app/controller.py

@@ -4,7 +4,7 @@
 import uuid
 
 import brightway2 as bw
-from PyQt5 import QtWidgets
+from PyQt5 import QtCore, QtWidgets
 from bw2data.backends.peewee import Exchange, sqlite3_lci_db
 from bw2data.project import ProjectDataset, SubstitutableDatabase
 
@@ -61,6 +61,7 @@ def connect_signals(self):
         signals.exchanges_deleted.connect(self.delete_exchanges)
         signals.exchanges_add.connect(self.add_exchanges)
         signals.exchange_amount_modified.connect(self.modify_exchange_amount)
+        signals.exchange_modified.connect(self.modify_exchange)
         # Calculation Setups
         signals.new_calculation_setup.connect(self.new_calculation_setup)
         signals.rename_calculation_setup.connect(self.rename_calculation_setup)
@@ -475,3 +476,25 @@ def modify_exchange_amount(self, exchange, value):
         exchange['amount'] = value
         exchange.save()
         signals.database_changed.emit(exchange['output'][0])
+
+    @staticmethod
+    @QtCore.pyqtSlot(object, str, object)
+    def modify_exchange(exchange, field, value):
+        # The formula field needs special handling.
+        if field == "formula":
+            if field in exchange and value == "":
+                # Remove formula entirely.
+                del exchange[field]
+                if "original_amount" in exchange:
+                    # Restore the original amount, if possible
+                    exchange["amount"] = exchange["original_amount"]
+                    del exchange["original_amount"]
+            if value:
+                # At least set the formula, possibly also store the amount
+                if field not in exchange:
+                    exchange["original_amount"] = exchange["amount"]
+                exchange[field] = value
+        else:
+            exchange[field] = value
+        exchange.save()
+        signals.database_changed.emit(exchange['output'][0])

activity_browser/app/signals.py

@@ -55,6 +55,7 @@ class Signals(QtCore.QObject):
     exchanges_deleted = QtCore.pyqtSignal(list)
     exchanges_add = QtCore.pyqtSignal(list, tuple)
     exchange_amount_modified = QtCore.pyqtSignal(object, float)
+    exchange_modified = QtCore.pyqtSignal(object, str, object)
 
     # Calculation Setups
     new_calculation_setup = QtCore.pyqtSignal()

activity_browser/app/ui/tables/__init__.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
-from .activity import ExchangeTable
+from .activity import (BiosphereExchangeTable, DownstreamExchangeTable,
+                       ProductExchangeTable, TechnosphereExchangeTable)
 from .history import ActivitiesHistoryTable
 from .impact_categories import CFTable, MethodsTable
 from .inventory import ActivitiesBiosphereTable, DatabasesTable